Spark-plug.



M. STANDlSH. SPARK PLUG. APPLICATION FILED MAY 17. 1911.

Patented Nov. 20, 1917.

UNITED STATES PATENT OFFICE.

MYLES STANDISH, F OMAHA, NEBRASKA.

SPARK-PLUG.

' Application filed May 17,

To all whom .z't may concern:

Be it known that I, MYLES citizen of the United States, residing atOmaha, in the county of Douglas and State of Nebraska, have inventedcertain new and useful Improvements in Spark-Plugs, of which thefollowing is a specification.

This invention relates to an improvement in spark plugs, and has for oneof its objec'ts to provide such a construction that the inner end of thecentral, insulated electrode will be prevented from becoming undulyheated, to thereby avoid preignition of the gas charges. Another objectis to pro- STANDISH, a

vide a metallic part or washer on the central electrode adapted toconduct heat and to cause heat to be communicated from the electrode toa conoidal face formed at the end of the stem of the insulating core, tocause combustion of soot and thereby avoid short circuits at the exposedend of the stem. Another object is to provide an insulating jacketwithin the stem of the insulating core, for the central electrode, sothat the spark plug will continue to be operative in instances when thestem becomes fractured or broken.

The invention also has reference to the formation of a recess disposedin the plane of the conoidal face of the stem and opening on the end ofsaid stem for containing a gasket and washer, and to the use of a sleevefor protecting one of the metals employed against the action of heat,said sleeve providing a support when the central electrode is pressedoutwardly of the insulating core for bracing and preventing vibration ofsaid electrode and for compressing the gasket.

With the.foregoing objects in view and others to be mentionedhereinafter, the invention presents a novel construction, combinationand arrangement of parts as described herein and claimed, and asillustrated in the accompanying drawing, wherea Figure 1 is a the sparkplug.

view in side elevation of Fig. 2 is a view of the same in longitudinalsection. Fig. 3 is an enlarged detail relating to Fig. 2.

Referring now to the drawing for a more particular description, theinvention is illustrated in connection with a longitudinally aperturedinsulating core 4, a tubular, metallic housing or ground electrode ofcon- Speciflcation of Letters Patent.

Patented Nov. 20, 1917.

1917. Serial No. 169,210.

ventional form for a spark plug, being in dicated at 5.

On account of the high degree of speed at which motor vehicles are oftendriven, the central, insulated electrodes, usually constructed of steel,attain a degree of heat sufficient to cause ignition of the gas chargesbefore the gas has become compressed, and known as preignition.

In order that this objectionable feature may be avoided, I provide forthe insulated electrode a central, electrical conductor 6, preferablyconstructed of steel, and a tube 7 of copper or similar metal having adegree of heat conductivity greater than steel.

It will be appreciated that the use of steel will provide rigidity forthis electrode and that steel will prevent warping. The copper, onaccount of its heat conductivity, will readily conduct the heat from theinner end of the electrode and cause it to be communicated to theinsulating core, and thence to the atmosphere to prevent pre-ignition ofthe gas charges. The proportion of steel and copper for the electrodesmay be changed, as may be required to correspond with difierent kinds ofmotors. In instances where the inner end of the electrode is subjectedto a degree of heat greater than ordinary, the tube of copper may have agreater thickness, and preferably the tube has a length substantiallyequal to the length of the central steel conductor.

On account of vibration and stresses directed thereto, the stem at ofthe insulating core occasionally becomes broken and separated from thebody of the core, or becomes fractured, to render the spark pluginoperative, from short circuits. In order that these objectionableresults may be avoided, the stem is provided with an insulating jacket8, preferably constructed of mica, which circumscribes the copper tube;and on account of this construction, the stem, if broken or fractured,will not become displaced or separated from the body of the insulatingcore, and the jacket 8 will prevent short circuits, in the instancesmentioned.

Numeral 9 indicates a depression or recess disposed at the longitudinalaxis and opening on the end of the stem a. said recess be ingcircumscribed by a conoidal face 10, at said terminal. The recess isadapted to contain a gasket 11 and a metallic ring or washer 12, thelatter operating as a heat-conducting element. It will be noted that therecess has a depth sufiicient, only, to contain these two elements, thisbeing a desirable feature so that the washer, when the parts areassembled, may be disposed substantially flush with the end of the stem,no depression being formed for a deposit of carbon therein, and alsothat said washer will be disposed in close proximity to the inclinedface At 13 is indicated a sleeve provided with a projection 14 at itsouter end, said sleeve and its projection being constructed ofnonincincrating metal and providing a support for member 12 when, by useof the screwcap 15, pressure is applied to the gasket 11,

the projection l-'l preferably bein secured to the central steelconductor. use of this construction, if the stem :2 is ractured orbroken, it will be pressed in a direction of the body of the insulatingcore, since the sleeve 13 and parts within the recess provide a supportfor this purpose.

uring operation, member 12 will become intensely heated since it is inengagement with the copper tube, and this heat, on account of theattenuated terminal, will be conducted to the conoidal face 10 of thestem, with the result that thereon will be effected, and short circuitsavoided. Member 12, preferably, is not threaded on the tube, and thisfeature facilitates assemblage of parts.

lVhile steel and copper have been specifically mentioned as the twometals used for the insulated electrode, it will be understood thatother metals may be substituted, one to provide rigidity and to prevent.warping, and the other to be, comparatively, a more ready conductor ofheat, and to be protected from the ignited gases by member 13 or itsequivalent.

I claim:

1. The herein improvement in spark plugs, comprising, in combinationwith an insulating core having its inner terminal provided with aconoidal face, an electrode traversing and projecting beyond the innerend of the core, and consisting of a central. conductor, a tubecircumscribing the central conductor, a coat of mica circumscribing thetube, said tube having a greater degree of heat conductivity than thecentral conductor, a metallic heat conducting element on the tubeadjacent to said conoidal face, and a metallic non-calcinating sleeveprovided with a pro jection and circumscribing that part of the tubewhich projects beyond the inner end of the insulating core.

In a spark plug the combination of an insulating core provided at itsinner terminal with an annular recess and a conoidal face outwardly ofsaid recess, an electrode trav- 10 for conducting heat thereto. 7

ersing and projecting beyond the core, and consisting of a centralconductor, a tube cir cumscribing and having a greater degree ofheat-conductivity than the central conductor, an insulating coat in theinsulating core and circumscribing a part of the tube, a heat conductingelement engaging the tube and disposed in said recess, and a metallicnoncalcinating sleeve provided with a projection and circumscribing thatpart of the tube outwardly of the insulating core.

3. In a spark plug, the combination of an insulating core provided atits inner terminal with a recess and formed outwardly in the plane ofsaid recess with a conoidal face, an electrode traversing and extendingbeyond the core and including, a central electrical conductor, a tubecircumscribing and having a greater degree of heat-conductivity thansaid conductor, packing in said recess abutting upon the insulatingcore, a heat coir ucting ring on the tube abutting upon the packing withits outer side disposed substantially flush with the end of theinsulating core, and a metallic, non-incinerating sleeve provided with aprojection and circumscribing that part of the tube outwardly of theinsulating core.

4. In a spa-r: plug, an electrode, an insulating core within theelectrode, said core having a stem provided with a recess openmg on itsend and having a conoidal face encircling the recess, a second electrodetraversing the recess and insulating 'core and provided with aprojection, a gasket in said recess, a metallic ring disposed on the second electrode in the plane of the conoidal face of said stem, a sleevebetween the projection of the second electrode and the metallic ring,and means to press the sleeve against the metallic ring for compressingthe gasket.

5. In a spark plug, an electrode, an insulating core within theelectrode, said core having a stem provided with a recess opening on itsend and having a conoidal face encircling the recess, a second electrodetraversing and having an extension outwardly of the end of theinsulating core, said second electrode including a steel conductor and acopper tube circumscribing said conductor, a screw cap mounted on thesecond electrode, a gasket in said recess, a metallic ring disposed onthe copper tube in the plane of the conoidal face of said stem, a sleeveoutwardly of the end of the insulating core on the extension of the tubeto abut upon the metallic ring for pressing the gasket against a wall ofthe recess and for disposing said ring substantially flush with the endof the stem of the insulating core when the screw cap is actuated.

In a spark plug, an electrode, an insulating core within the electrode,said core having a stem provided with a recess opening on its end, asecond electrode traversing the recess and insulating core and having anextension disposed outwardly of the end of the stem, said secondelectrode including a steel conductor and a copper tube circumscribingthe steel conductor, a gasket in said recess, a metallic ring on thecopper tube, a sleeve on the extension of the second electrode, saidscrew cap being revoluble for disposing said ring substantially flushwith the end of the sleeve of the insulating core in engagement with thegasket.

7. In a spark plug, an electrode, an insulating core within theelectrode, said core having a stem provided with a recess opening on itsend and having a conoidal face encircling the recess, a second electrodetraversing and having an extension outwardly of the end of theinsulating core, said second electrode consisting of a steel conductor,a copper tube circumscribing said conductor and an insulating coat inthe stem encircling the tube, a

of the insulating core screw cap mounted on the second electrode,

a metallic ring disa gasket in said recess,

posed on the copper tube in the plane of the conoidal face of said stem,wardly of the end of the insulating core on the extension of the tube toabut upon the metallic ring for pressing the gasket against a wall ofthe recess and disposing said ring substantially flush with the end ofthe stern of the insulating core when the screw cap is actuated.

8. In a spark plug, an electrode, an insulating core within theelectrode, said core having a stem provided with a recess opening on itsend a second electrode traversing the recess an. insulating core andhaving an extension disposed outwardly of the end of the stem, saidsecond electrode consisting of a steel conductor, a copper tubecircumscribing the steel conductor and an insulating jacket in the stemcircumscribing the tube, a gasket in said recess, a metallic ring on thecopper tube, a sleeve on the extension of the second electrode, saidscrew cap a sleeve outbeing revoluble for disposing said ringsubstantially flush with the end of the sleeve of the insulating coreinengagement with the gasket.

9. In a spark plug the combination of an insulating core having a stemprovided at its inner terminal with an annular recess, an electrodetraversing and projecting beyond the stem of the core, and consisting ofa central conductor, a tube circumscribing and having a greater degreeof heat-conductivity than the central conductor, an insulating acket inthe stem of the insulating core and circumscribing the tube, a asket 1nthe recess, a washer on the tube an disposed in said recess, and ametallic non-calcinating sleeve provided with a projection andcircumscribing that part of the tube outwardly of the sleeve of theinsulating core.

10. In a spark plug, an electrode, an insulating core within theelectrode provided with a stem, a second electrode traversing theinsulating core and having an extension disposed outwardly of the end ofthe stem,

said second electrode consisting of a steel conductor and a copper tubecircumscribing the steel conductor, an insulating aeket 1n the stemcircumscribing the tube, and a nonincinerating sleeve circumscribing theextension of the second electrode.

11. In a spark plug, an electrode, an insulating core within theelectrode provided with 'a stem, a second electrode traversing theinsulating core and having an extension disposed outwardly of the end ofthe stem, said second electrode consisting of a steel conductor and acopper tube circumscribing the steel conductor, and a non-incineratingsleeve circumscribing the extension of the second electrode.

In testimony whereof, I have afiixed my signature in presence of twow1tnesses.

. MYLES STANDISH.

Witnesses:

HIRAM A. S'rrmsns, ARTHUR H. Srrmons.

